/* RTL dead store elimination.
- Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+ Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
Contributed by Richard Sandiford <rsandifor@codesourcery.com>
and Kenneth Zadeck <zadeck@naturalbridge.com>
#include "target.h"
/* This file contains three techniques for performing Dead Store
- Elimination (dse).
+ Elimination (dse).
* The first technique performs dse locally on any base address. It
is based on the cselib which is a local value numbering technique.
This technique is local to a basic block but deals with a fairly
general addresses.
-
+
* The second technique performs dse globally but is restricted to
base addresses that are either constant or are relative to the
frame_pointer.
stores, only one store to an address is necessary because those
stores die at the end of the function.
- 3) Set up the global dataflow equations based on processing the
+ 3) Set up the global dataflow equations based on processing the
info parsed in the first step.
4) Solve the dataflow equations.
These are expensive and cumbersome in our bitmap formulation so
care has been taken to avoid large vectors filled with 1s. See
the comments in bb_info and in the dataflow confluence functions
- for details.
+ for details.
There are two places for further enhancements to this algorithm:
-
+
1) The original dse which was embedded in a pass called flow also
did local address forwarding. For example in
with the same mode and alias set. The backout in this case is a
little more graceful than (a). In this case the slot is unmarked
as being a spill slot and if final address comes out to be based
- off the frame pointer, the global algorithm handles this slot.
+ off the frame pointer, the global algorithm handles this slot.
c) For any pass that may prespill, there is currently no
mechanism to tell the dse pass that the slot being used has the
struct insn_info;
/* This structure holds information about a candidate store. */
-struct store_info
+struct store_info
{
/* False means this is a clobber. */
true, this is -1. Otherwise, it is the index into the group
table. */
int group_id;
-
+
/* This is the cselib value. */
cselib_val *cse_base;
/* This structure holds information about a load. These are only
built for rtx bases. */
-struct read_info
+struct read_info
{
/* The id of the mem group of the base address. */
int group_id;
/* One of these records is created for each insn. */
-struct insn_info
+struct insn_info
{
/* Set true if the insn contains a store but the insn itself cannot
be deleted. This is set if the insn is a parallel and there is
static alloc_pool insn_info_pool;
/* The linked list of stores that are under consideration in this
- basic block. */
+ basic block. */
static insn_info_t active_local_stores;
-struct bb_info
+struct bb_info
{
/* Pointer to the insn info for the last insn in the block. These
/* The set of store positions that exist in this block before a wild read. */
bitmap gen;
-
+
/* The set of load positions that exist in this block above the
same position of a store. */
bitmap kill;
memory. There are also not many of the rtx bases because they are
very limited in scope. */
-struct group_info
+struct group_info
{
/* The actual base of the address. */
rtx rtx_base;
hard_frame_pointer. */
bool frame_related;
- /* A mem wrapped around the base pointer for the group in order to
- do read dependency. */
+ /* A mem wrapped around the base pointer for the group in order to do
+ read dependency. It must be given BLKmode in order to encompass all
+ the possible offsets from the base. */
rtx base_mem;
-
+
/* Canonized version of base_mem's address. */
rtx canon_base_addr;
positions in the global bitmaps. It is only created after all of
the all of stores have been scanned and we know which ones we
care about. */
- int *offset_map_n, *offset_map_p;
- int offset_map_size_n, offset_map_size_p;
+ int *offset_map_n, *offset_map_p;
+ int offset_map_size_n, offset_map_size_p;
};
typedef struct group_info *group_info_t;
typedef const struct group_info *const_group_info_t;
/* This structure holds the set of changes that are being deferred
when removing read operation. See replace_read. */
-struct deferred_change
+struct deferred_change
{
/* The mem that is being replaced. */
/* The set of clear_alias_sets that have been disqualified because
there are loads or stores using a different mode than the alias set
- was registered with. */
+ was registered with. */
static bitmap disqualified_clear_alias_sets = NULL;
/* The group that holds all of the clear_alias_sets. */
static bool stores_off_frame_dead_at_return;
/* Counter for stats. */
-static int globally_deleted;
-static int locally_deleted;
-static int spill_deleted;
-
+static int globally_deleted;
+static int locally_deleted;
+static int spill_deleted;
+
static bitmap all_blocks;
/* The number of bits used in the global bitmaps. */
/*----------------------------------------------------------------------------
Zeroth step.
- Initialization.
+ Initialization.
----------------------------------------------------------------------------*/
/* Hashtable callbacks for maintaining the "bases" field of
static int
clear_alias_mode_eq (const void *p1, const void *p2)
{
- const struct clear_alias_mode_holder * h1
+ const struct clear_alias_mode_holder * h1
= (const struct clear_alias_mode_holder *) p1;
- const struct clear_alias_mode_holder * h2
+ const struct clear_alias_mode_holder * h2
= (const struct clear_alias_mode_holder *) p2;
return h1->alias_set == h2->alias_set;
}
static hashval_t
clear_alias_mode_hash (const void *p)
{
- const struct clear_alias_mode_holder *holder
+ const struct clear_alias_mode_holder *holder
= (const struct clear_alias_mode_holder *) p;
return holder->alias_set;
}
{
struct clear_alias_mode_holder tmp_holder;
void **slot;
-
+
tmp_holder.alias_set = alias_set;
slot = htab_find_slot (clear_alias_mode_table, &tmp_holder, NO_INSERT);
gcc_assert (*slot);
-
+
return (struct clear_alias_mode_holder *) *slot;
}
static group_info_t
get_group_info (rtx base)
{
- struct group_info tmp_gi;
- group_info_t gi;
+ struct group_info tmp_gi;
+ group_info_t gi;
void **slot;
if (base)
*slot = gi = (group_info_t) pool_alloc (rtx_group_info_pool);
gi->rtx_base = base;
gi->id = rtx_group_next_id++;
- gi->base_mem = gen_rtx_MEM (QImode, base);
+ gi->base_mem = gen_rtx_MEM (BLKmode, base);
gi->canon_base_addr = canon_rtx (base);
gi->store1_n = BITMAP_ALLOC (NULL);
gi->store1_p = BITMAP_ALLOC (NULL);
gi->store2_p = BITMAP_ALLOC (NULL);
gi->group_kill = BITMAP_ALLOC (NULL);
gi->process_globally = false;
- gi->frame_related =
+ gi->frame_related =
(base == frame_pointer_rtx) || (base == hard_frame_pointer_rtx);
gi->offset_map_size_n = 0;
gi->offset_map_size_p = 0;
scratch = BITMAP_ALLOC (NULL);
rtx_store_info_pool
- = create_alloc_pool ("rtx_store_info_pool",
+ = create_alloc_pool ("rtx_store_info_pool",
sizeof (struct store_info), 100);
read_info_pool
- = create_alloc_pool ("read_info_pool",
+ = create_alloc_pool ("read_info_pool",
sizeof (struct read_info), 100);
insn_info_pool
- = create_alloc_pool ("insn_info_pool",
+ = create_alloc_pool ("insn_info_pool",
sizeof (struct insn_info), 100);
bb_info_pool
- = create_alloc_pool ("bb_info_pool",
+ = create_alloc_pool ("bb_info_pool",
sizeof (struct bb_info), 100);
rtx_group_info_pool
- = create_alloc_pool ("rtx_group_info_pool",
+ = create_alloc_pool ("rtx_group_info_pool",
sizeof (struct group_info), 100);
deferred_change_pool
- = create_alloc_pool ("deferred_change_pool",
+ = create_alloc_pool ("deferred_change_pool",
sizeof (struct deferred_change), 10);
rtx_group_table = htab_create (11, invariant_group_base_hash,
stores_off_frame_dead_at_return = !cfun->stdarg;
init_alias_analysis ();
-
+
if (clear_alias_sets)
clear_alias_group = get_group_info (NULL);
else
/* Delete all of the store_info recs from INSN_INFO. */
-static void
+static void
free_store_info (insn_info_t insn_info)
{
store_info_t store_info = insn_info->store_rec;
insn_info->store_rec = NULL;
}
-
-struct insn_size {
- int size;
- rtx insn;
-};
-
-
-/* Add an insn to do the add inside a x if it is a
- PRE/POST-INC/DEC/MODIFY. D is an structure containing the insn and
- the size of the mode of the MEM that this is inside of. */
+/* Callback for for_each_inc_dec that emits an INSN that sets DEST to
+ SRC + SRCOFF before insn ARG. */
static int
-replace_inc_dec (rtx *r, void *d)
+emit_inc_dec_insn_before (rtx mem ATTRIBUTE_UNUSED,
+ rtx op ATTRIBUTE_UNUSED,
+ rtx dest, rtx src, rtx srcoff, void *arg)
{
- rtx x = *r;
- struct insn_size *data = (struct insn_size *)d;
- switch (GET_CODE (x))
- {
- case PRE_INC:
- case POST_INC:
- {
- rtx r1 = XEXP (x, 0);
- rtx c = gen_int_mode (data->size, Pmode);
- emit_insn_before (gen_rtx_SET (Pmode, r1,
- gen_rtx_PLUS (Pmode, r1, c)),
- data->insn);
- return -1;
- }
-
- case PRE_DEC:
- case POST_DEC:
- {
- rtx r1 = XEXP (x, 0);
- rtx c = gen_int_mode (-data->size, Pmode);
- emit_insn_before (gen_rtx_SET (Pmode, r1,
- gen_rtx_PLUS (Pmode, r1, c)),
- data->insn);
- return -1;
- }
-
- case PRE_MODIFY:
- case POST_MODIFY:
- {
- /* We can reuse the add because we are about to delete the
- insn that contained it. */
- rtx add = XEXP (x, 0);
- rtx r1 = XEXP (add, 0);
- emit_insn_before (gen_rtx_SET (Pmode, r1, add), data->insn);
- return -1;
- }
-
- default:
- return 0;
- }
-}
-
+ rtx insn = (rtx)arg;
-/* If X is a MEM, check the address to see if it is PRE/POST-INC/DEC/MODIFY
- and generate an add to replace that. */
+ if (srcoff)
+ src = gen_rtx_PLUS (GET_MODE (src), src, srcoff);
-static int
-replace_inc_dec_mem (rtx *r, void *d)
-{
- rtx x = *r;
- if (x != NULL_RTX && MEM_P (x))
- {
- struct insn_size data;
+ /* We can reuse all operands without copying, because we are about
+ to delete the insn that contained it. */
- data.size = GET_MODE_SIZE (GET_MODE (x));
- data.insn = (rtx) d;
+ emit_insn_before (gen_rtx_SET (VOIDmode, dest, src), insn);
- for_each_rtx (&XEXP (x, 0), replace_inc_dec, &data);
-
- return -1;
- }
- return 0;
+ return -1;
}
/* Before we delete INSN, make sure that the auto inc/dec, if it is
{
rtx note = find_reg_note (insn, REG_INC, NULL_RTX);
if (note)
- for_each_rtx (&insn, replace_inc_dec_mem, insn);
+ for_each_inc_dec (&insn, emit_inc_dec_insn_before, insn);
}
-/* Delete the insn and free all of the fields inside INSN_INFO. */
+/* Delete the insn and free all of the fields inside INSN_INFO. */
static void
delete_dead_store_insn (insn_info_t insn_info)
check_for_inc_dec (insn_info->insn);
if (dump_file)
{
- fprintf (dump_file, "Locally deleting insn %d ",
+ fprintf (dump_file, "Locally deleting insn %d ",
INSN_UID (insn_info->insn));
if (insn_info->store_rec->alias_set)
- fprintf (dump_file, "alias set %d\n",
+ fprintf (dump_file, "alias set %d\n",
(int) insn_info->store_rec->alias_set);
else
fprintf (dump_file, "\n");
free_store_info (insn_info);
read_info = insn_info->read_rec;
-
+
while (read_info)
{
read_info_t next = read_info->next;
store2 = group->store2_p;
ai = i;
}
-
- if (bitmap_bit_p (store1, ai))
+
+ if (!bitmap_set_bit (store1, ai))
bitmap_set_bit (store2, ai);
- else
+ else
{
- bitmap_set_bit (store1, ai);
if (i < 0)
{
if (group->offset_map_size_n < ai)
pool_free (read_info_pool, *ptr);
*ptr = next;
}
- else
+ else
ptr = &(*ptr)->next;
}
insn_info->wild_read = true;
{
switch (GET_CODE (x))
{
- case MEM:
- return MEM_READONLY_P (x);
-
case CONST:
case CONST_INT:
case CONST_DOUBLE:
}
}
-/* Take all reasonable action to put the address of MEM into the form
- that we can do analysis on.
+/* Take all reasonable action to put the address of MEM into the form
+ that we can do analysis on.
The gold standard is to get the address into the form: address +
OFFSET where address is something that rtx_varies_p considers a
obtained from that.
If that fails, we try cselib to get a value we can at least use
- locally. If that fails we return false.
-
+ locally. If that fails we return false.
+
The GROUP_ID is set to -1 for cselib bases and the index of the
group for non_varying bases.
canon_address (rtx mem,
alias_set_type *alias_set_out,
int *group_id,
- HOST_WIDE_INT *offset,
+ HOST_WIDE_INT *offset,
cselib_val **base)
{
+ enum machine_mode address_mode
+ = targetm.addr_space.address_mode (MEM_ADDR_SPACE (mem));
rtx mem_address = XEXP (mem, 0);
rtx expanded_address, address;
+ int expanded;
+
/* Make sure that cselib is has initialized all of the operands of
the address before asking it to do the subst. */
fprintf (dump_file, "found alias set %d\n", (int) alias_set);
if (bitmap_bit_p (clear_alias_sets, alias_set))
{
- struct clear_alias_mode_holder *entry
+ struct clear_alias_mode_holder *entry
= clear_alias_set_lookup (alias_set);
/* If the modes do not match, we cannot process this set. */
if (entry->mode != GET_MODE (mem))
{
if (dump_file)
- fprintf (dump_file,
- "disqualifying alias set %d, (%s) != (%s)\n",
- (int) alias_set, GET_MODE_NAME (entry->mode),
+ fprintf (dump_file,
+ "disqualifying alias set %d, (%s) != (%s)\n",
+ (int) alias_set, GET_MODE_NAME (entry->mode),
GET_MODE_NAME (GET_MODE (mem)));
-
+
bitmap_set_bit (disqualified_clear_alias_sets, alias_set);
return false;
}
*alias_set_out = 0;
- cselib_lookup (mem_address, Pmode, 1);
+ cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem));
if (dump_file)
{
fprintf (dump_file, "\n");
}
- /* Use cselib to replace all of the reg references with the full
- expression. This will take care of the case where we have
-
- r_x = base + offset;
- val = *r_x;
-
- by making it into
+ /* First see if just canon_rtx (mem_address) is const or frame,
+ if not, try cselib_expand_value_rtx and call canon_rtx on that. */
+ address = NULL_RTX;
+ for (expanded = 0; expanded < 2; expanded++)
+ {
+ if (expanded)
+ {
+ /* Use cselib to replace all of the reg references with the full
+ expression. This will take care of the case where we have
- val = *(base + offset);
- */
+ r_x = base + offset;
+ val = *r_x;
- expanded_address = cselib_expand_value_rtx (mem_address, scratch, 5);
+ by making it into
- /* If this fails, just go with the mem_address. */
- if (!expanded_address)
- expanded_address = mem_address;
+ val = *(base + offset); */
- /* Split the address into canonical BASE + OFFSET terms. */
- address = canon_rtx (expanded_address);
+ expanded_address = cselib_expand_value_rtx (mem_address,
+ scratch, 5);
- *offset = 0;
+ /* If this fails, just go with the address from first
+ iteration. */
+ if (!expanded_address)
+ break;
+ }
+ else
+ expanded_address = mem_address;
- if (dump_file)
- {
- fprintf (dump_file, "\n after cselib_expand address: ");
- print_inline_rtx (dump_file, expanded_address, 0);
- fprintf (dump_file, "\n");
+ /* Split the address into canonical BASE + OFFSET terms. */
+ address = canon_rtx (expanded_address);
- fprintf (dump_file, "\n after canon_rtx address: ");
- print_inline_rtx (dump_file, address, 0);
- fprintf (dump_file, "\n");
- }
+ *offset = 0;
- if (GET_CODE (address) == CONST)
- address = XEXP (address, 0);
+ if (dump_file)
+ {
+ if (expanded)
+ {
+ fprintf (dump_file, "\n after cselib_expand address: ");
+ print_inline_rtx (dump_file, expanded_address, 0);
+ fprintf (dump_file, "\n");
+ }
- if (GET_CODE (address) == PLUS && CONST_INT_P (XEXP (address, 1)))
- {
- *offset = INTVAL (XEXP (address, 1));
- address = XEXP (address, 0);
- }
+ fprintf (dump_file, "\n after canon_rtx address: ");
+ print_inline_rtx (dump_file, address, 0);
+ fprintf (dump_file, "\n");
+ }
- if (const_or_frame_p (address))
- {
- group_info_t group = get_group_info (address);
+ if (GET_CODE (address) == CONST)
+ address = XEXP (address, 0);
- if (dump_file)
- fprintf (dump_file, " gid=%d offset=%d \n", group->id, (int)*offset);
- *base = NULL;
- *group_id = group->id;
- }
- else
- {
- *base = cselib_lookup (address, Pmode, true);
- *group_id = -1;
+ if (GET_CODE (address) == PLUS
+ && CONST_INT_P (XEXP (address, 1)))
+ {
+ *offset = INTVAL (XEXP (address, 1));
+ address = XEXP (address, 0);
+ }
- if (*base == NULL)
+ if (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (mem))
+ && const_or_frame_p (address))
{
+ group_info_t group = get_group_info (address);
+
if (dump_file)
- fprintf (dump_file, " no cselib val - should be a wild read.\n");
- return false;
+ fprintf (dump_file, " gid=%d offset=%d \n",
+ group->id, (int)*offset);
+ *base = NULL;
+ *group_id = group->id;
+ return true;
}
+ }
+
+ *base = cselib_lookup (address, address_mode, true, GET_MODE (mem));
+ *group_id = -1;
+
+ if (*base == NULL)
+ {
if (dump_file)
- fprintf (dump_file, " varying cselib base=%d offset = %d\n",
- (*base)->value, (int)*offset);
+ fprintf (dump_file, " no cselib val - should be a wild read.\n");
+ return false;
}
+ if (dump_file)
+ fprintf (dump_file, " varying cselib base=%u:%u offset = %d\n",
+ (*base)->uid, (*base)->hash, (int)*offset);
return true;
}
{
if (__builtin_expect (s_info->is_large, false))
{
- if (!bitmap_bit_p (s_info->positions_needed.large.bmap, pos))
- {
- s_info->positions_needed.large.count++;
- bitmap_set_bit (s_info->positions_needed.large.bmap, pos);
- }
+ if (bitmap_set_bit (s_info->positions_needed.large.bmap, pos))
+ s_info->positions_needed.large.count++;
}
else
s_info->positions_needed.small_bitmask
{
if (GET_CODE (XEXP (mem, 0)) == SCRATCH)
{
- if (dump_file)
+ if (dump_file)
fprintf (dump_file, " adding wild read for (clobber (mem:BLK (scratch))\n");
add_wild_read (bb_info);
insn_info->cannot_delete = true;
bitmap store2 = clear_alias_group->store2_p;
gcc_assert (GET_MODE (mem) != BLKmode);
-
- if (bitmap_bit_p (store1, spill_alias_set))
+
+ if (!bitmap_set_bit (store1, spill_alias_set))
bitmap_set_bit (store2, spill_alias_set);
- else
- bitmap_set_bit (store1, spill_alias_set);
-
+
if (clear_alias_group->offset_map_size_p < spill_alias_set)
clear_alias_group->offset_map_size_p = spill_alias_set;
-
+
store_info = (store_info_t) pool_alloc (rtx_store_info_pool);
if (dump_file)
{
/* In the restrictive case where the base is a constant or the
frame pointer we can do global analysis. */
-
- group_info_t group
+
+ group_info_t group
= VEC_index (group_info_t, rtx_group_vec, group_id);
-
+
store_info = (store_info_t) pool_alloc (rtx_store_info_pool);
set_usage_bits (group, offset, width);
del = false;
else if (s_info->alias_set)
{
- struct clear_alias_mode_holder *entry
+ struct clear_alias_mode_holder *entry
= clear_alias_set_lookup (s_info->alias_set);
/* Generally, spills cannot be processed if and of the
references to the slot have a different mode. But if
fprintf (dump_file, " trying spill store in insn=%d alias_set=%d\n",
INSN_UID (ptr->insn), (int) s_info->alias_set);
}
- else if ((s_info->group_id == group_id)
+ else if ((s_info->group_id == group_id)
&& (s_info->cse_base == base))
{
HOST_WIDE_INT i;
if (dump_file)
fprintf (dump_file, " trying store in insn=%d gid=%d[%d..%d)\n",
- INSN_UID (ptr->insn), s_info->group_id,
+ INSN_UID (ptr->insn), s_info->group_id,
(int)s_info->begin, (int)s_info->end);
/* Even if PTR won't be eliminated as unneeded, if both
the value of store_info. If it is, set the rhs to NULL to
keep it from being used to remove a load. */
{
- if (canon_true_dependence (s_info->mem,
+ if (canon_true_dependence (s_info->mem,
GET_MODE (s_info->mem),
s_info->mem_addr,
mem, mem_addr, rtx_varies_p))
if (del)
{
insn_info_t insn_to_delete = ptr;
-
+
if (last)
last->next_local_store = ptr->next_local_store;
else
active_local_stores = ptr->next_local_store;
-
+
delete_dead_store_insn (insn_to_delete);
}
else
last = ptr;
-
+
ptr = next;
}
-
+
/* Finish filling in the store_info. */
store_info->next = insn_info->store_rec;
insn_info->store_rec = store_info;
static void
dump_insn_info (const char * start, insn_info_t insn_info)
{
- fprintf (dump_file, "%s insn=%d %s\n", start,
+ fprintf (dump_file, "%s insn=%d %s\n", start,
INSN_UID (insn_info->insn),
insn_info->store_rec ? "has store" : "naked");
}
...
... <- A
- and change it into
+ and change it into
r2 <- r1
A <- r1
...
went ok. */
static bool
-replace_read (store_info_t store_info, insn_info_t store_insn,
+replace_read (store_info_t store_info, insn_info_t store_insn,
read_info_t read_info, insn_info_t read_insn, rtx *loc,
bitmap regs_live)
{
for (this_insn = insns; this_insn != NULL_RTX; this_insn = NEXT_INSN (this_insn))
note_stores (PATTERN (this_insn), look_for_hardregs, regs_set);
-
+
bitmap_and_into (regs_set, regs_live);
if (!bitmap_empty_p (regs_set))
{
if (dump_file)
{
- fprintf (dump_file,
+ fprintf (dump_file,
"abandoning replacement because sequence clobbers live hardregs:");
df_print_regset (dump_file, regs_set);
}
-
+
BITMAP_FREE (regs_set);
return false;
}
{
deferred_change_t deferred_change =
(deferred_change_t) pool_alloc (deferred_change_pool);
-
+
/* Insert this right before the store insn where it will be safe
from later insns that might change it before the read. */
emit_insn_before (insns, store_insn->insn);
-
+
/* And now for the kludge part: cselib croaks if you just
return at this point. There are two reasons for this:
-
+
1) Cselib has an idea of how many pseudos there are and
that does not include the new ones we just added.
-
+
2) Cselib does not know about the move insn we added
above the store_info, and there is no way to tell it
about it, because it has "moved on".
-
+
Problem (1) is fixable with a certain amount of engineering.
Problem (2) is requires starting the bb from scratch. This
could be expensive.
-
+
So we are just going to have to lie. The move/extraction
insns are not really an issue, cselib did not see them. But
the use of the new pseudo read_insn is a real problem because
and when we are finished with the block, we undo this. We
keep a table of mems to get rid of. At the end of the basic
block we can put them back. */
-
+
*loc = read_info->mem;
deferred_change->next = deferred_change_list;
deferred_change_list = deferred_change;
deferred_change->loc = loc;
deferred_change->reg = read_reg;
-
+
/* Get rid of the read_info, from the point of view of the
rest of dse, play like this read never happened. */
read_insn->read_rec = read_info->next;
}
return true;
}
- else
+ else
{
if (dump_file)
{
HOST_WIDE_INT offset = 0;
HOST_WIDE_INT width = 0;
alias_set_type spill_alias_set = 0;
- cselib_val *base = NULL;
+ cselib_val *base = NULL;
int group_id;
read_info_t read_info;
/* Skip the clobbers. */
while (!store_info->is_set)
store_info = store_info->next;
-
+
if (store_info->alias_set == spill_alias_set)
{
if (dump_file)
the frame pointer and offset is a constant. */
insn_info_t i_ptr = active_local_stores;
insn_info_t last = NULL;
-
+
if (dump_file)
{
if (width == -1)
{
bool remove = false;
store_info_t store_info = i_ptr->store_rec;
-
+
/* Skip the clobbers. */
while (!store_info->is_set)
store_info = store_info->next;
-
+
/* There are three cases here. */
if (store_info->group_id < 0)
/* We have a cselib store followed by a read from a
const base. */
- remove
- = canon_true_dependence (store_info->mem,
+ remove
+ = canon_true_dependence (store_info->mem,
GET_MODE (store_info->mem),
store_info->mem_addr,
mem, mem_addr, rtx_varies_p);
-
+
else if (group_id == store_info->group_id)
{
/* This is a block mode load. We may get lucky and
canon_true_dependence may save the day. */
if (width == -1)
- remove
- = canon_true_dependence (store_info->mem,
+ remove
+ = canon_true_dependence (store_info->mem,
GET_MODE (store_info->mem),
store_info->mem_addr,
mem, mem_addr, rtx_varies_p);
-
+
/* If this read is just reading back something that we just
stored, rewrite the read. */
- else
+ else
{
if (store_info->rhs
&& offset >= store_info->begin
/* The bases are the same, just see if the offsets
overlap. */
- if ((offset < store_info->end)
+ if ((offset < store_info->end)
&& (offset + width > store_info->begin))
remove = true;
}
}
-
- /* else
+
+ /* else
The else case that is missing here is that the
bases are constant but different. There is nothing
to do here because there is no overlap. */
-
+
if (remove)
{
if (dump_file)
i_ptr = i_ptr->next_local_store;
}
}
- else
+ else
{
insn_info_t i_ptr = active_local_stores;
insn_info_t last = NULL;
{
bool remove = false;
store_info_t store_info = i_ptr->store_rec;
-
+
if (dump_file)
fprintf (dump_file, " processing cselib load against insn %d\n",
INSN_UID (i_ptr->insn));
return 0;
if (!store_info->alias_set)
- remove = canon_true_dependence (store_info->mem,
+ remove = canon_true_dependence (store_info->mem,
GET_MODE (store_info->mem),
store_info->mem_addr,
mem, mem_addr, rtx_varies_p);
-
+
if (remove)
{
if (dump_file)
dump_insn_info ("removing from active", i_ptr);
-
+
if (last)
last->next_local_store = i_ptr->next_local_store;
else
return 0;
}
-/* A for_each_rtx callback in which DATA points the INSN_INFO for
+/* A for_each_rtx callback in which DATA points the INSN_INFO for
as check_mem_read_rtx. Nullify the pointer if i_m_r_m_r returns
true for any part of *LOC. */
arg = TREE_CHAIN (arg), idx++)
{
enum machine_mode mode = TYPE_MODE (TREE_VALUE (arg));
- rtx reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1), link, tmp;
+ rtx reg, link, tmp;
+ reg = targetm.calls.function_arg (&args_so_far, mode, NULL_TREE, true);
if (!reg || !REG_P (reg) || GET_MODE (reg) != mode
|| GET_MODE_CLASS (mode) != MODE_INT)
return false;
if (tmp)
args[idx] = tmp;
- FUNCTION_ARG_ADVANCE (args_so_far, mode, NULL_TREE, 1);
+ targetm.calls.function_arg_advance (&args_so_far, mode, NULL_TREE, true);
}
if (arg != void_list_node || idx != nargs)
return false;
insn_info->prev_insn = bb_info->last_insn;
insn_info->insn = insn;
bb_info->last_insn = insn_info;
-
+
+ if (DEBUG_INSN_P (insn))
+ {
+ insn_info->cannot_delete = true;
+ return;
+ }
/* Cselib clears the table for this case, so we have to essentially
do the same. */
{
if (dump_file)
dump_insn_info ("removing from active", i_ptr);
-
+
if (last)
last->next_local_store = i_ptr->next_local_store;
else
them. */
if ((GET_CODE (PATTERN (insn)) == CLOBBER)
|| volatile_refs_p (PATTERN (insn))
- || (flag_non_call_exceptions && may_trap_p (PATTERN (insn)))
+ || insn_could_throw_p (insn)
|| (RTX_FRAME_RELATED_P (insn))
|| find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX))
insn_info->cannot_delete = true;
-
+
body = PATTERN (insn);
if (GET_CODE (body) == PARALLEL)
{
mems_found += record_store (body, bb_info);
if (dump_file)
- fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n",
+ fprintf (dump_file, "mems_found = %d, cannot_delete = %s\n",
mems_found, insn_info->cannot_delete ? "true" : "false");
/* If we found some sets of mems, add it into the active_local_stores so
being deleted, then the insn can not be deleted. */
while (store_info)
{
- if ((store_info->group_id == -1)
+ if ((store_info->group_id == -1)
&& (store_info->cse_base == base))
{
del = true;
}
else
last = insn_info;
-
+
insn_info = insn_info->next_local_store;
}
}
{
basic_block bb;
bitmap regs_live = BITMAP_ALLOC (NULL);
-
- cselib_init (false);
+
+ cselib_init (0);
all_blocks = BITMAP_ALLOC (NULL);
bitmap_set_bit (all_blocks, ENTRY_BLOCK);
bitmap_set_bit (all_blocks, EXIT_BLOCK);
rtx insn;
cse_store_info_pool
- = create_alloc_pool ("cse_store_info_pool",
+ = create_alloc_pool ("cse_store_info_pool",
sizeof (struct store_info), 100);
active_local_stores = NULL;
cselib_clear_table ();
-
+
/* Scan the insns. */
FOR_BB_INSNS (bb, insn)
{
if (INSN_P (insn))
df_simulate_one_insn_forwards (bb, insn, regs_live);
}
-
+
/* This is something of a hack, because the global algorithm
is supposed to take care of the case where stores go dead
at the end of the function. However, the global
store_info = store_info->next;
if (store_info->alias_set && !i_ptr->cannot_delete)
delete_dead_store_insn (i_ptr);
- else
+ else
if (store_info->group_id >= 0)
{
- group_info_t group
+ group_info_t group
= VEC_index (group_info_t, rtx_group_vec, store_info->group_id);
if (group->frame_related && !i_ptr->cannot_delete)
delete_dead_store_insn (i_ptr);
unsigned int i;
group_info_t group;
- for (i = 0; VEC_iterate (group_info_t, rtx_group_vec, i, group); i++)
+ FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group)
{
/* For all non stack related bases, we only consider a store to
be deletable if there are two or more stores for that
for the position. We do this because the stack related
stores can be deleted if their is no read between them and
the end of the function.
-
+
To make this work in the current framework, we take the stack
related bases add all of the bits from store1 into store2.
This has the effect of making the eligible even if there is
bitmap_ior_into (group->store2_n, group->store1_n);
bitmap_ior_into (group->store2_p, group->store1_p);
if (dump_file)
- fprintf (dump_file, "group %d is frame related ", i);
+ fprintf (dump_file, "group %d is frame related ", i);
}
group->offset_map_size_n++;
group->process_globally = false;
if (dump_file)
{
- fprintf (dump_file, "group %d(%d+%d): ", i,
+ fprintf (dump_file, "group %d(%d+%d): ", i,
(int)bitmap_count_bits (group->store2_n),
(int)bitmap_count_bits (group->store2_p));
bitmap_print (dump_file, group->store2_n, "n ", " ");
unused. */
current_position = 1;
- for (i = 0; VEC_iterate (group_info_t, rtx_group_vec, i, group); i++)
+ FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group)
{
bitmap_iterator bi;
unsigned int j;
}
EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi)
{
- bitmap_set_bit (group->group_kill, current_position);
+ bitmap_set_bit (group->group_kill, current_position);
group->offset_map_p[j] = current_position++;
group->process_globally = true;
}
if (dump_file)
{
- bitmap_print (dump_file, clear_alias_sets,
+ bitmap_print (dump_file, clear_alias_sets,
"clear alias sets ", "\n");
- bitmap_print (dump_file, disqualified_clear_alias_sets,
+ bitmap_print (dump_file, disqualified_clear_alias_sets,
"disqualified clear alias sets ", "\n");
}
memset (group->offset_map_n, 0, sizeof(int) * group->offset_map_size_n);
memset (group->offset_map_p, 0, sizeof(int) * group->offset_map_size_p);
bitmap_clear (group->group_kill);
-
+
/* Remove the disqualified positions from the store2_p set. */
bitmap_and_compl_into (group->store2_p, disqualified_clear_alias_sets);
-
+
/* We do not need to process the store2_n set because
alias_sets are always positive. */
EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi)
{
- bitmap_set_bit (group->group_kill, current_position);
+ bitmap_set_bit (group->group_kill, current_position);
group->offset_map_p[j] = current_position++;
group->process_globally = true;
}
\f
/*----------------------------------------------------------------------------
Third step.
-
+
Build the bit vectors for the transfer functions.
----------------------------------------------------------------------------*/
/* Note that this is NOT a general purpose function. Any mem that has
an alias set registered here expected to be COMPLETELY unaliased:
- i.e it's addresses are not and need not be examined.
+ i.e it's addresses are not and need not be examined.
It is known that all references to this address will have this
alias set and there are NO other references to this address in the
- function.
+ function.
Currently the only place that is known to be clean enough to use
- this interface is the code that assigns the spill locations.
+ this interface is the code that assigns the spill locations.
All of the mems that have alias_sets registered are subjected to a
very powerful form of dse where function calls, volatile reads and
- writes, and reads from random location are not taken into account.
+ writes, and reads from random location are not taken into account.
It is also assumed that these locations go dead when the function
returns. This assumption could be relaxed if there were found to
elements. So when we see a mode mismatch, we just bail. */
-void
-dse_record_singleton_alias_set (alias_set_type alias_set,
+void
+dse_record_singleton_alias_set (alias_set_type alias_set,
enum machine_mode mode)
{
struct clear_alias_mode_holder tmp_holder;
disqualified_clear_alias_sets = BITMAP_ALLOC (NULL);
clear_alias_mode_table = htab_create (11, clear_alias_mode_hash,
clear_alias_mode_eq, NULL);
- clear_alias_mode_pool = create_alloc_pool ("clear_alias_mode_pool",
+ clear_alias_mode_pool = create_alloc_pool ("clear_alias_mode_pool",
sizeof (struct clear_alias_mode_holder), 100);
}
/* Remove ALIAS_SET from the sets of stack slots being considered. */
-void
+void
dse_invalidate_singleton_alias_set (alias_set_type alias_set)
{
if ((!gate_dse()) || !alias_set)
/* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL
may be NULL. */
-static void
+static void
scan_stores_nospill (store_info_t store_info, bitmap gen, bitmap kill)
{
while (store_info)
{
HOST_WIDE_INT i;
- group_info_t group_info
+ group_info_t group_info
= VEC_index (group_info_t, rtx_group_vec, store_info->group_id);
if (group_info->process_globally)
for (i = store_info->begin; i < store_info->end; i++)
/* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL
may be NULL. */
-static void
+static void
scan_stores_spill (store_info_t store_info, bitmap gen, bitmap kill)
{
while (store_info)
{
if (store_info->alias_set)
{
- int index = get_bitmap_index (clear_alias_group,
+ int index = get_bitmap_index (clear_alias_group,
store_info->alias_set);
if (index != 0)
{
/* If this insn reads the frame, kill all the frame related stores. */
if (insn_info->frame_read)
{
- for (i = 0; VEC_iterate (group_info_t, rtx_group_vec, i, group); i++)
+ FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group)
if (group->process_globally && group->frame_related)
{
if (kill)
bitmap_ior_into (kill, group->group_kill);
- bitmap_and_compl_into (gen, group->group_kill);
+ bitmap_and_compl_into (gen, group->group_kill);
}
}
while (read_info)
{
- for (i = 0; VEC_iterate (group_info_t, rtx_group_vec, i, group); i++)
+ FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group)
{
if (group->process_globally)
{
something else with a different constant
base. */
if ((read_info->group_id < 0)
- && canon_true_dependence (group->base_mem,
- QImode,
+ && canon_true_dependence (group->base_mem,
+ GET_MODE (group->base_mem),
group->canon_base_addr,
read_info->mem, NULL_RTX,
rtx_varies_p))
}
}
}
-
+
read_info = read_info->next;
}
}
{
if (read_info->alias_set)
{
- int index = get_bitmap_index (clear_alias_group,
+ int index = get_bitmap_index (clear_alias_group,
read_info->alias_set);
if (index != 0)
{
bitmap_clear_bit (gen, index);
}
}
-
+
read_info = read_info->next;
}
}
insn_info = bb_info->last_insn;
else
insn_info = find_insn_before_first_wild_read (bb_info);
-
+
/* In the spill case or in the no_spill case if there is no wild
read in the block, we will need a kill set. */
if (insn_info == bb_info->last_insn)
else
bb_info->kill = BITMAP_ALLOC (NULL);
}
- else
+ else
if (bb_info->kill)
BITMAP_FREE (bb_info->kill);
this phase. */
if (insn_info->insn && INSN_P (insn_info->insn))
{
- /* Process the read(s) last. */
+ /* Process the read(s) last. */
if (for_spills)
{
scan_stores_spill (insn_info->store_rec, bb_info->gen, bb_info->kill);
scan_stores_nospill (insn_info->store_rec, bb_info->gen, bb_info->kill);
scan_reads_nospill (insn_info, bb_info->gen, bb_info->kill);
}
- }
+ }
insn_info = insn_info->prev_insn;
}
{
/* The gen set is all 0's for the exit block except for the
frame_pointer_group. */
-
+
if (stores_off_frame_dead_at_return)
{
unsigned int i;
group_info_t group;
-
- for (i = 0; VEC_iterate (group_info_t, rtx_group_vec, i, group); i++)
+
+ FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group)
{
if (group->process_globally && group->frame_related)
bitmap_ior_into (bb_info->gen, group->group_kill);
{
RESET_BIT (unreachable_blocks, bb->index);
FOR_EACH_EDGE (e, ei, bb->preds)
- {
+ {
mark_reachable_blocks (unreachable_blocks, e->src);
- }
+ }
}
}
sbitmap_iterator sbi;
bitmap all_ones = NULL;
unsigned int i;
-
+
sbitmap_ones (unreachable_blocks);
FOR_ALL_BB (bb)
group_info_t group;
all_ones = BITMAP_ALLOC (NULL);
- for (j = 0; VEC_iterate (group_info_t, rtx_group_vec, j, group); j++)
+ FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, j, group)
bitmap_ior_into (all_ones, group->group_kill);
}
if (!bb_info->out)
out set of the src of E. If the various in or out sets are not
there, that means they are all ones. */
-static void
+static bool
dse_confluence_n (edge e)
{
bb_info_t src_info = bb_table[e->src->index];
bitmap_copy (src_info->out, dest_info->in);
}
}
+ return true;
}
/* Propagate the info from the out to the in set of BB_INDEX's basic
- block. There are three cases:
+ block. There are three cases:
1) The block has no kill set. In this case the kill set is all
ones. It does not matter what the out set of the block is, none of
{
/* Case 3 above. */
if (bb_info->in)
- return bitmap_ior_and_compl (bb_info->in, bb_info->gen,
+ return bitmap_ior_and_compl (bb_info->in, bb_info->gen,
bb_info->out, bb_info->kill);
else
{
bb_info->in = BITMAP_ALLOC (NULL);
- bitmap_ior_and_compl (bb_info->in, bb_info->gen,
+ bitmap_ior_and_compl (bb_info->in, bb_info->gen,
bb_info->out, bb_info->kill);
return true;
}
static void
dse_step4 (void)
{
- df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0,
- dse_confluence_n, dse_transfer_function,
- all_blocks, df_get_postorder (DF_BACKWARD),
+ df_simple_dataflow (DF_BACKWARD, NULL, dse_confluence_0,
+ dse_confluence_n, dse_transfer_function,
+ all_blocks, df_get_postorder (DF_BACKWARD),
df_get_n_blocks (DF_BACKWARD));
if (dump_file)
{
/* There may have been code deleted by the dce pass run before
this phase. */
- if (insn_info->insn
+ if (insn_info->insn
&& INSN_P (insn_info->insn)
&& (!insn_info->cannot_delete)
&& (!bitmap_empty_p (v)))
/* Try to delete the current insn. */
deleted = true;
-
+
/* Skip the clobbers. */
while (!store_info->is_set)
store_info = store_info->next;
else
{
HOST_WIDE_INT i;
- group_info_t group_info
+ group_info_t group_info
= VEC_index (group_info_t, rtx_group_vec, store_info->group_id);
-
+
for (i = store_info->begin; i < store_info->end; i++)
{
int index = get_bitmap_index (group_info, i);
-
+
if (dump_file)
- fprintf (dump_file, "i = %d, index = %d\n", (int)i, index);
+ fprintf (dump_file, "i = %d, index = %d\n", (int)i, index);
if (index == 0 || !bitmap_bit_p (v, index))
{
if (dump_file)
- fprintf (dump_file, "failing at i = %d\n", (int)i);
+ fprintf (dump_file, "failing at i = %d\n", (int)i);
deleted = false;
break;
}
/* We do want to process the local info if the insn was
deleted. For instance, if the insn did a wild read, we
no longer need to trash the info. */
- if (insn_info->insn
+ if (insn_info->insn
&& INSN_P (insn_info->insn)
&& (!deleted))
{
scan_reads_nospill (insn_info, v, NULL);
}
}
-
+
insn_info = insn_info->prev_insn;
}
}
bool deleted = false;
/* There may have been code deleted by the dce pass run before
this phase. */
- if (insn_info->insn
+ if (insn_info->insn
&& INSN_P (insn_info->insn)
&& (!insn_info->cannot_delete)
&& (!bitmap_empty_p (v)))
/* Try to delete the current insn. */
store_info_t store_info = insn_info->store_rec;
deleted = true;
-
+
while (store_info)
{
if (store_info->alias_set)
{
- int index = get_bitmap_index (clear_alias_group,
+ int index = get_bitmap_index (clear_alias_group,
store_info->alias_set);
if (index == 0 || !bitmap_bit_p (v, index))
{
break;
}
}
- else
+ else
deleted = false;
store_info = store_info->next;
}
if (deleted && dbg_cnt (dse))
{
if (dump_file)
- fprintf (dump_file, "Spill deleting insn %d\n",
+ fprintf (dump_file, "Spill deleting insn %d\n",
INSN_UID (insn_info->insn));
check_for_inc_dec (insn_info->insn);
delete_insn (insn_info->insn);
insn_info->insn = NULL;
}
}
-
- if (insn_info->insn
+
+ if (insn_info->insn
&& INSN_P (insn_info->insn)
&& (!deleted))
{
scan_stores_spill (insn_info->store_rec, v, NULL);
scan_reads_spill (insn_info->read_rec, v, NULL);
}
-
+
insn_info = insn_info->prev_insn;
}
}
/*----------------------------------------------------------------------------
Seventh step.
- Destroy everything left standing.
+ Destroy everything left standing.
----------------------------------------------------------------------------*/
-static void
+static void
dse_step7 (bool global_done)
{
unsigned int i;
group_info_t group;
basic_block bb;
-
- for (i = 0; VEC_iterate (group_info_t, rtx_group_vec, i, group); i++)
+
+ FOR_EACH_VEC_ELT (group_info_t, rtx_group_vec, i, group)
{
free (group->offset_map_n);
free (group->offset_map_p);
pass to process the spills. These are special in that they are
totally transparent, i.e, there is no aliasing issues that need
to be considered. This means that the wild reads that kill
- everything else do not apply here. */
+ everything else do not apply here. */
if (clear_alias_sets && dse_step2_spill ())
{
if (!did_global)
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